Paper making process



7 No Drawing.

Patented Oct. 18, 1932 j UNITED STATES JAMES R. SIMPSON, OF WISCONSINRAPIDS, WISCONSIN,

WORKS, OF BELOIT, WISCONSIN, A CORPORATION OF WISCONSIN PAPER MAKINGPROCESS Application filed June 18,

The present invention relates to a paper making process and moreparticularly to those steps in the process of making a sheet of paperinvolving the formation of the sheet on the wire of a F ourdrinier papermaking machine.

In such formation of a sheet of paper, it has heretofore been founddesirable in making many grades of paper to effect a vibratory orshaking motion in that part of the machine including the Fourdrinierwire in order to interlace and evenly distribute the fibers from whichthe sheet is formed.

In paper making processes as heretofore practiced, this shakingapplication has been applied ordinarily beginning at a point where thestock flows onto the Fourdrinier wire or immediately thereafter andwithout reference to the condition of the stock or the speed offormation of the sheet. By such former processes, control of theformation of the sheet has been haphazard and in many instances theshaking action has been found to be detrimental rather thanadvantageous.

By the present invention I propose to overcome such difliculties andcontrol the formation of the sheet so far as the shaking of the fibersin the stock from which the sheet is formed is concerned by onlyapplying the shake beginning at that portion of the F ourdrinier wirewhere a certain portion of water has drained from the stock and thefibers from which the sheet is forming have already taken an initial setin the formation of the final sheet. I have found that at this point theshaking action is desirable and necessary to smooth out and strengthenthe fibrous formation while application of the shake or vibration atpoints in advance thereof may often prove detrimental.

By utilization of this principle, it is possible to make a sheet ofrelatively high grade paper at extremely high speeds and without specialpreparation of the stock by beating or otherwise and the attendanttendency to weaken the sheet formation by deterioration of the fibersfrom which the sheet is formed.

As an example of the application of the principles of this invention, Ihave found it 1930. Serial no. 462,144.

possible to make relatively high grade magazine paper in a Fourdriniermachine at speeds approximating one thousand feet per minute from stockof approximately sixty percent ground wood and forty percent bleachedsulphite with no special preparation of the stock and no use of beaters,the stock soused comes from the pulp mill over deckers and is slushedthrough a light running Jordan engine directly into the head box of themachine and onto the Fourdrinier wire. This particular grade of paperhas a base weight of AssI GNoR TO BELOIT moiv approximately thirty-fivepounds and due to the fact that there is so much water in thestock whenit first flows on the wire, the stock does not form immediately, andtherefore, in accordance with the principle of this invention, I havefound it most advantageous to apply the shake approximately at thecenter of the F ourdrinier wire at a rate of about 350 to 400 vibrationsper minute and at an amplitude of about three-eighths inch." In makingheavier paper, the shake is applied nearer to the breast roll of theFourdrinier paper making machine but in all instances the shake is notapplied in advance of the point where sufiicient water has drainedthrough the wire to bring about an initiation of the formation of thefibers. At this point, the application of a shaking action has beenfound by me to be most advantageous in the formation of a strong,uniform and superiorsheet of paper at high rates of speed. By soapplying the shaking action in the formation of the sheet, it ispossible to leave the fibers of the stock longer and consequently thecompleted'sheet of paper has a better test as to tearing and as tofolding qualities. 7

In carrying outthe process of this invention, I have found itadvantageous to employ a shaking mechanism such as disclosed in UnitedStates Letters Patent No. Re. 17,381, reissued on the th day of July,1929, to Alonzo Aldrich. This mechanism is convenient for the practicingof the process of my invention because of its ready adaptability forconnection of the shaking mechanism at various points along theFourdrinier wire and the disconnection of the shaking mechanism fromthose portions of the wire which it is not desirable to shake.

In accordance with the process of the present invention, the shake isnot applied until the stock has flowed on the wire and reached such acondition that the shake becomes effective in properly smoothing out thefibrous formation. By virtue of this fact, preliminary working of thefibers as by beating is greatly minimized.

As a general thing, it may be stated'that jhe vigorous shake should beapplied approx fiber formation during a substantial distance of travelon a portion of the wire free from lateral movement and applying avigorous shaking action to the stock after said initial fiber formationto efiect proper distribution and interlacing of the fibers in the sheetbeing formed.

In testimony whereof I have hereunto subscribed my name at WisconsinRapids, Wood County, Wis.

JAMES R. SIMPSON.

lmately at the center of the Fourdrinier wire for the lighter weights ofpaper while for in that the stock is not shaken until some water hasbeen drained therefrom and furthermore the life of the Fourdrinier wireis lengthened due to the fact that in practically all instances the wireis reciprocated across the faces of the suction boxes'and is not wornout by grooves formed therein.

In general I may state that in applying the principles of this inventionin stock of heavier consistency the shake is initiated closer to thebreast roll while with stock of li hter consistency the initiation ofthe shake I o 0 1s brought about at greater distances from the breastroll as previously pointed out herein.

I am of course aware that details of practicing the process of myinvention may be varied and thatthe process may be effected by variousmechanisms, and I therefore do not purpose limiting the patent grantedupon this invention otherwise than necessitated by the prior art.

I claim as my invention: 7

1. The method of forming a paper web which comprises flowing paper stockonto a traveling perforated surface, draining a predetermined quantityof water from the stock without substantially shaking the fibers.

therein to form an initial deposit of loosely matted fibers on theperforated surface under relatively quiescent conditions, andsubsequently subjecting said deposited fibers to a shaking action toforms an interlaced fiber we 2. In the process of making paper at highspeeds on a Fourdrinier type of paper machine having a forming wire, thesteps which compriseflowing the paper stock onto a traveling Fourdrinierwire,=permitting an initial

